:root {
  --background-color: #2a3d51;
}

* {
  margin: 0;
  padding: 0;
}

body {
  width: 100vw;
  height: 100vh;
  background-color: var(--background-color);
  display: flex;
  justify-content: center;
  align-items: center;
  font-family: Shijie;
}

@font-face {
  font-family: "Shijie";
  src: url("../intro3S/汉仪正圆-45S.ttf");
}

a.bt{
  color: #fff;
  font-size: 24px;
  text-decoration: none;
  text-transform: uppercase;
  border: 4px solid;
  padding: 12px 24px;
  position: relative;
}

a.bt::before,a.bt::after{
  content: "";
  position: absolute;
  background-color: var(--background-color);
  width: 24px;
  height: 4px;
  transform: skew(-30deg);
  transition: 0.5s ease-in-out;
}

a.bt::before{
  top: -4px;
  left: 20%;
}

a.bt::after{
  bottom: -4px;
  right: 20%;
}

a.bt:hover::before{
  left: 80%;
}

a.bt:hover::after{
  right: 80%;
}
